YOKOMO BD9 MID Conversion Kit by Arrowmax AM-910003  [AM-910003]

BD9 MID conversion kit

This Arrowmax conversion kit reconfigures Yokomo BD9 chassis for a mid-motor layout to support specific tuning goals for on-track handling. The kit is offered in distinct editions and groups components that change the motor position, upper deck, pulley arrangement and chassis stiffness so builders can evaluate different flex and balance settings without altering the BD9 core drivetrain.

Key components referenced in the original release include a choice between a 2.25mm carbon fibre chassis or a 2.0mm alloy chassis variant, a 2.0mm carbon fibre upper deck, a 7075 single-piece motor mount and redesigned 7075 centre pulleys, plus a chassis stiffener that enables access to multiple flex settings. The maker notes the mid-motor layout affects steering response, traction and cornering speed when applied to BD9 cars.

Use this kit to experiment with weight distribution and chassis flex on BD9 platforms, for example when adjusting front/rear balance or tuning for higher corner entry steering. Installation requires standard BD9 disassembly to replace the main chassis and motor mount components and realign pulley and belt geometry to the mid-motor configuration.

The conversion kit is intended for BD9 owners who want to test mid-motor geometry and chassis flex variations without fabricating custom parts, offering a packaged set of structural and drivetrain pieces to support controlled tuning work.